Each ton of dry stover contains about 3.6 pounds of P2O5 and 20 pounds of
K2O.

A ton of stover contains $18 of P2O5 and K2O at $0.75 per pound of these
nutrients.

orn
stover baling removes valuable crop nutrients from the field. The amount and
value of phosphorus (P) and potassium (K) in stover clearly should be considered
a cost of stover baling. Other essential plant nutrients, such as nitrogen,
calcium, magnesium sulfur, and the micronutrient are removed in the stover
and may be figured into the nutrient cost of stover baling, especially in
low nutrient soils and with long-term stover removal.

The amount of dry stover produced by a corn crop is approximately equal to
the weight of grain at 15.5% moisture. Therefore, a 150 bushel per acre corn
crop would leave about 4 tons of stover in the field. The usual assumption
is that about 60% of the stover is gathered, approximately 2.5 tons per acre.

Corn stover contains about 3.6 lb P2O5 and 20 lb K2O on a per ton basis (based
on stover concentrations of 0.18% P2O5 and 0.99% K2O). The 2.5 tons per acre
removed from a field producing 150 bushels per acre contains about 9 pounds
of P2O5 and 50 pounds of K2O. The value of these nutrients at current prices
($0.75 per pound of P2O5 or K2O) is about $44 per acre or $18 per ton of stover.

Crop residue is not only an important recyclable source of crop nutrients,
it also helps reduce soil erosion and replenishes soil organic matter. Soil
organic matter is responsible for many soil quality characteristics, such
as soil structure, porosity, drainage, aeration, and water holding capacity.
Corn stover removal eventually will lead to reduced soil quality through a
reduction in soil organic matter. Compaction during stover removal is another
factor that may reduce soil quality and should be minimized.

Fig. 1. Don't overlook the lost value of phosphorus and potassium when baling
cornstalks.